In Afghanistan, the big looming question is what's next. In a phone call this week, President Obama told Afghan President Hamid Karzai that the United States will move ahead with plans to pull all U.S. troops out of his country by the end of the year, since Karzai refuses to sign a bilateral security agreement. Yesterday, NATO allies said they would follow suit.

Upcoming elections will bring a new president to power in Kabul and the U.S. hopes that could bring about a way to keep some troops in Afghanistan. Normally for more we turn to NPR's Sean Carberry in Kabul, but Sean is not in Afghanistan, he's here in Washington in our studios this morning. Sean, good to see you.

SEAN CARBERRY, BYLINE: Good to be with you, David.

GREENE: So tell us what the U.S. and NATO allies are thinking here and trying to accomplish by making a declaration like this to Karzai?

CARBERRY: Well, it's really a statement of an evolving policy over the last couple of months. Increasingly, U.S. and NATO officials have come to realize that Karzai isn't likely to sign the security agreement. So they've been putting forward kind of a two track strategy.

One is to plan for the possibility that the next president, when he comes into office sometime later this year, would sign a security deal and allow the U.S. to keep as many as 10,000 troops in the country for training purposes and some counterterrorism operations. But they're also planning for the possibility that the next president might not be in office soon enough that they can get this done by the end of the year to put it in place, so they are planning for a possible total withdrawal.

So this has been evolving, but this is really sort of putting a button on where things are right now.

GREENE: So the evolution here to total withdrawal, we should say, comes from a place - I mean President Obama had hoped to keep these 10,000 troops you're talking about - not combat troops but just a troop presence in the country - for a while.

CARBERRY: Right. Right. And this has been a known policy for some time, that this would be part of a continued training mission. Afghan forces still need support in a number of areas. So this - as I say, this policy has been under negotiation for well over a year between the two countries.

GREENE: Remind us what we've seen from Karzai over his final months in office.

CARBERRY: Well, what we've seen is really a turn away from the U.S. and arguably a turn towards the Taliban. His rhetoric about the U.S. has grown far more acrimonious. He has been accusing the U.S. again of civilian casualties, of a number of things. He's been calling the Taliban brothers, reaching out to them, not criticizing their activities in the country as much. And the feeling is that he's been trying to get a last minute peace deal with the Taliban.

Which even many of his close advisers say is highly unlikely. The Taliban have long said they will not negotiate with Karzai. And he's even made this bizarre set of conditions that he won't sign the security agreement with the U.S. until peace talks start with the Taliban. But the Taliban don't want the security agreement so they have every incentive now not to talk, not to enter a peace process. That then would prevent the security agreement.

So it's sort of a strange set of conditions he's put in motion.

GREENE: There are going be elections to replace Karzai in April but it will take a few months to sort out who won, probably. I mean does the United States actually have reason to think that there will be a successor in place and they can get an agreement and actually, you know, make a decision to keep some troops there?

CARBERRY: Looking at the election calendar, it's anywhere from possibly late June to as far out as September before the whole thing is resolved. It's likely to go two rounds. There are long periods to evaluate and to certify the vote. So it does push the envelope. If this drags on too long it's going to be difficult for the U.S. to be able to then get this deal signed and go forward.

It's going to be even more difficult for NATO countries because they have to wait for the U.S. deal to be signed before they can then commit their troops. So it's causing a lot more anxiety the longer this drags out.

GREENE: All right. Our Kabul correspondent, Sean Carberry, joining us this time in our studios in Washington. Sean, thanks a lot.